The present invention relates to carbon black suitable for use in a tire tread where high abrasion resistance is required, and more particularly to carbon black having novel characteristics useful particularly for use in the tread of a large-size tire for trucks, buses, etc.
There are many kinds of carbon black for reinforcement of rubber having various characteristics. The characteristics of carbon black are a major factor determining various properties of rubber containing, added thereto, carbon black and various compounding ingredients (hereinafter referred to as "compounded rubber").
For this reason, in compounding carbon black with rubber, carbon black having characteristics suitable for final applications of the compounded rubber has been usually selected and used.
For example, it is known that carbon black having a small particle diameter and a large specific surface area, such as SAF (Super Abrasion Furnace Black) N110 and ISAF (Intermediate Super Abrasion Furnace Black) N220, are useful as carbon black for a tire tread where high abrasion resistance is required.
However, because of the small particle diameter, SAF(N110) and ISAF(N220) increase the viscosity, hardness, etc. of the kneaded product in the step of mixing with a rubber component, which makes it difficult to homogeneously disperse carbon black in the rubber component. This brought about a problem that not only the energy and time necessary for the homogeneous dispersion of carbon black was increased but also the quality was deteriorated due to a lowering in the dispersion processability of the formed compounded rubber.
Accordingly, an object of the present invention is to provide carbon black for a tire tread having novel characteristics which can be easily dispersed in a rubber component even in the case of a small particle diameter, prevent deterioration of the quality of the compounded rubber, and impart high abrasion resistance to the compounded rubber.